JP6544221B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter provided with a power converter.

  Vehicles such as electric vehicles and hybrid vehicles are equipped with a power converter such as an inverter that converts DC power into AC power, and a converter that converts DC power into DC power of different voltages. For example, Patent Document 1 below discloses a power conversion device in which both an inverter and a converter are accommodated in a case as a case.

  Power converters such as inverters and converters are configured to flow a large current and generate a large amount of heat. Therefore, in the power conversion device of Patent Document 1 described above, the refrigerant flow path is provided in the partition part that divides the two power converters in the case. By flowing the refrigerant through the refrigerant flow path, the ambient temperature inside the power conversion device can be kept low by the cooling effect of the refrigerant. Furthermore, this power converter is configured such that one of the two power converters is fixed at a position near the refrigerant flow path in the partition. Thus, the power converter fixed to the partition portion exchanges heat with the partition portion cooled by the refrigerant. As a result, this power converter can be cooled by the divider.

JP, 2012-217316, A

  By the way, assuming that the power converter of the above-mentioned patent document 1 removes and repairs a power converter from a case, and replaces it with another power converter, the power converter is fixed structure by bolt fastening. It is comprised so that it may be fixed to a partition part. According to this fixed structure, it becomes possible to repeat attachment and detachment of the power converter with respect to the partition. In this fixing structure, instead of using a nut in which the male screw shaft of the bolt is screwed, a female screw hole is provided in the partition and a fixed structure in which the male screw shaft of the bolt is screwed in this female screw hole is adopted. Is preferred. In this case, since a dedicated nut is not required, the number of parts can be reduced and the fixing structure can be simplified.

  However, in this fixing structure, when the female screw hole is not a through hole, the boss portion in which the female screw hole is formed in the partition is located on the opposite side to the one power converter fixed to the partition. Project towards the power converter of At this time, since the boss portion interferes with bringing the other power converter closer to the partition portion, the other power converter is disposed at a position deviated from the boss portion (female screw hole). Here, when a female screw hole is provided at a position close to the refrigerant flow path in the partition to enhance the cooling effect of one of the power converters, the other electric power converter will be away from the refrigerant flow path in the partition . Therefore, when this fixed structure is adopted, although one power converter can be efficiently cooled by the refrigerant, there is a problem that the effect of cooling the other power converter is reduced. Therefore, in designing this fixed structure, a configuration capable of efficiently cooling these two power converters without reducing the cooling effect of both is required.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a power conversion device capable of improving the cooling performance of both of two power converters partitioned by a partition portion constituting a refrigerant flow path. It is a thing.

One aspect of the present invention is
A first power converter (10) and a second power converter (20) each performing power conversion;
A case (30) accommodating the first power converter and the second power converter;
A partition portion (32) which partitions the first power converter and the second power converter housed in the case and which constitutes a refrigerant flow path (36) through which the refrigerant flows;
A fastening bolt (51) for securing the fixed portion (21) of at least one of the first power converter and the second power converter to the partition portion;
The male screw shaft (52) of the fastening bolt is inserted into the bolt insertion hole (22) provided in the fixed part, and screwed into the female screw hole (37) provided in the partition part,
The female screw hole penetrates the partition portion ,
Among the first power converter and the second power converter, the power converter positioned on the tip end side of the male screw shaft of the fastening bolt is disposed on a virtual axis (L) passing through the male screw shaft,
The fastening bolt is configured to be screwed with the female screw hole without the male screw shaft penetrating the female screw hole toward the axial tip end, and the female screw hole is a thin sheet from the axial tip side of the male screw shaft In the power converter (1), which is closed by a member (54) .

  In the above power converter, the fixed portion of at least one of the first power converter and the second power converter is fixed to the partition by a fastening bolt. The fastening bolt is configured to be screwed into a female screw hole provided in the partition portion so as to penetrate the partition portion. According to this structure, compared with the case where the female screw hole is a non-through hole, the part having the female screw hole in the partition can be made thinner. Thus, the height of the bosses projecting toward the other power converter in the partition can be reduced. As a result, the other power converter can be disposed close to the partition without avoiding the boss, and the reduction in the cooling effect of the power converter can be suppressed.

As mentioned above, according to the above-mentioned mode, when one power converter is fixed to a partition by bolt fastening, it can control that a cooling effect of the other power converter declines, and both of two power converters Cooling performance can be improved.
The reference numerals in parentheses described in the claims and the means for solving the problems indicate the correspondence with the specific means described in the embodiments described later, and the technical scope of the present invention is limited. It is not a thing.

The figure which shows the outline | summary of the power converter device of this embodiment. II-II arrow directional cross-sectional view of FIG. III-III arrow directional cross-sectional view of FIG. The enlarged view of A area | region of FIG. The inverter circuit diagram of the power converter device of this embodiment.

  Hereinafter, embodiments of the power converter will be described with reference to the drawings.

  In the drawings of the present specification, unless otherwise specified, the first direction which is the longitudinal direction (longitudinal direction) of the case accommodating the power converter is indicated by the arrow X, and the second direction which is the lateral direction of the case is An arrow Y is shown, and a third direction orthogonal to both the first direction and the second direction is shown by an arrow Z.

  As FIGS. 1 to 3 are referred to, the power conversion device 1 of the present embodiment includes a first power converter 10, a second power converter 20, and a case 30.

  The first power converter 10 is an inverter that converts direct current power into alternating current power. Hereinafter, it is also referred to as "inverter 10." The second power converter 20 is a converter that converts DC power into DC power of different voltage. Hereinafter, it is also referred to as “converter 20”. Both the inverter 10 and the converter 20 are devices that perform power conversion. The power conversion device 1 is a power conversion device suitable for mounting on a vehicle such as an electric vehicle or a hybrid vehicle by a combination of the inverter 10 and the converter 20.

  The case 30 is a box-shaped member that accommodates the inverter 10, the converter 20, and a plurality of other electronic components. The case 30 includes four side wall portions 31 and a partition portion 32 which divides an internal space surrounded by the four side wall portions 31. The case 30 is an automobile part that requires light weight and high dimensional accuracy, and is typically manufactured by an aluminum die casting method using an aluminum material.

  The partition portion 32 is configured as a part of the case 30. The partition portion 32 is a flat portion extending along a plane (a plane defined by both the first direction X and the second direction Y) orthogonal to all the four side wall portions 31. Thus, the case 30 has a substantially H-shaped cross section shown in FIGS. 2 and 3. According to the partition portion 32, the internal space of the case 30 is divided into a first space 33 accommodating at least the inverter 10 and a second space 34 accommodating at least the converter 20. Each of the first space 33 and the second space 34 is closed by a cover 35.

  The partition portion 32 constitutes a refrigerant flow path 36 through which the refrigerant flows by closing the concave portion 32a in which the lower surface facing the second space 34 is recessed by the base portion 21 constituting the mounting surface of the converter 20. . That is, the converter 20 itself divides a part of the refrigerant flow path 36. The base portion 21 is made of the same aluminum material as the case 30. The base portion 21 is in contact with the partition portion 32 via a sealing material (not shown) such as a liquid gasket or rubber, whereby the airtightness of the refrigerant channel 36 is secured.

  Since the refrigerant flow path 36 is formed by the converter 20 closing the recess 32 a of the partition portion 32, the case 30 can be cooled by the refrigerant flowing through the refrigerant flow path 36, and the converter 20 can also be cooled. . Further, by providing the refrigerant flow path 36 in the partition portion 32, it is possible to prevent the heat interference between the inverter 10 and the converter 20 which both generate heat. Furthermore, by providing the refrigerant flow path 36 in the partition portion 32, interference of electromagnetic noise between the inverter 10 and the converter 20 can be prevented.

  For example, natural refrigerants such as water and ammonia, water mixed with ethylene glycol antifreeze, fluorocarbon refrigerants such as Fluorinat, fluorocarbon refrigerants such as HCFC 123 and HFC 134a as refrigerants to be circulated through the refrigerant flow path 36 An alcohol-based refrigerant such as methanol or alcohol, a ketone-based refrigerant such as acetone, or the like can be used.

  The inverter 10 is a laminate in which a plurality of semiconductor modules 11 containing semiconductor elements and a plurality of cooling pipes (cooling units) 14 for circulating a refrigerant for cooling the semiconductor modules 11 are alternately stacked in the first direction X Is equipped. The semiconductor module 11 is sandwiched by the cooling pipe 14 from both sides. The semiconductor module 11 incorporates switching elements such as IGBTs and diodes such as FWDs.

  Each inflow part of the plurality of cooling pipes 14 is connected to the refrigerant supply header 15 for supplying the refrigerant from the outside, and each outflow part of the plurality of cooling pipes 14 is connected to the refrigerant discharge header 16 for discharging the refrigerant to the outside. It is connected. Therefore, when the refrigerant flowing from the refrigerant supply header 15 into the inflow portion of the cooling pipe 14 flows through the refrigerant flow path in the cooling pipe 14, the semiconductor modules 11 located on both sides in the first direction X of the cooling pipe 14 are After cooling, the refrigerant is discharged from the outflow portion of the cooling pipe 14 to the refrigerant discharge header 16. As the refrigerant to be circulated in the cooling pipe 14, the same refrigerant as the refrigerant to be circulated in the refrigerant channel 36 can be used.

  The semiconductor module 11 includes a control terminal 12 and an electrode terminal 13. The control terminal 12 is connected to the control circuit board 17, and the electrode terminal 13 is connected to a metal bus bar (not shown). A control current for controlling the switching elements of the semiconductor module 11 is input to the semiconductor module 11 through the control terminal 12. The controlled power of the semiconductor module 11 is input to and output from the semiconductor module 11 through the electrode terminal 13.

  The inverter 10 further includes a reactor 18, a capacitor 19 and the like which are elements constituting an inverter circuit 10a described later. The reactor 18 constitutes a part of a booster circuit for boosting the input voltage to the semiconductor module 11. The capacitor 19 is configured as a smoothing capacitor that smoothes the input voltage or the boosted voltage. The reactor 18 is accommodated in the first space 33 in a state of being disposed adjacent to one side of the plurality of semiconductor modules 11 in the first direction X, as shown in FIGS. 1 and 2. The capacitor 19 is accommodated in the first space 33 in a state of being arranged side by side with respect to the plurality of semiconductor modules 11 and the reactor 18 as shown in FIGS. 1 and 3.

  As shown in FIG. 3, the converter 20 accommodated in the second space 34 of the case 30 is fixed to the partition portion 32 by the fastening bolt 51 in the fixing portion 50. Refer to FIG. 4 for the details of the fixing portion 50.

  As shown in FIG. 4, the fastening bolt 51 has a diameter greater than that of the male screw shaft 52 that can be screwed into the female screw hole 37 provided in the partition 32 and the male screw shaft 52 provided at one end of the male screw shaft 52. And a head 53 having a large outer shape in the direction. The fastening bolt 51 is made of a metal material. The fastening bolt 51 is typically configured as a hexagonal bolt in which the shape of the head portion 53 is a substantially regular hexagon. Alternatively, the fastening bolt 51 may be configured as a cap bolt operated by a tool such as a wrench. The bolt insertion hole 22 is a through hole which is not provided with a female screw such as the female screw hole 37 and which exceeds the diameter of the male screw shaft 52 of the fastening bolt 51.

  In fixing portion 50, male screw shaft 52 of fastening bolt 51 is inserted through bolt insertion hole 22 provided in base portion 21 which is a fixed portion of converter 20, and screwed into female screw hole 37 provided in the partition portion. It is correct. The female screw hole 37 penetrates the partition portion 32 and communicates the first space 33 of the case 30 with the second space 34. The female screw hole 37 is provided at a position close to the refrigerant flow path 36 in the partition portion 32 in order to enhance the cooling effect of the converter 20.

  When the screwing operation of the fastening bolt 51 is performed, the base portion 21 of the converter 20 is fixed to the partition portion 32 by being sandwiched between the head portion 53 of the fastening bolt 51 and the partition portion 32. On the other hand, when the screwing operation of the fastening bolt 51 is performed so that the screwing of the male screw shaft 52 with respect to the female screw hole 37 is released, the fixing of the base portion 21 of the converter 20 to the partition portion 32 is released. As a result, the converter 20 can be repeatedly attached to and detached from the partition portion 32, and the converter 20 can be removed from the case 30 and repaired or replaced with another converter.

  The female screw hole 37 is a through hole that penetrates the partition 32. Therefore, compared with the case where the female screw hole 37 is a non-through hole, it is possible to make the portion of the partition 32 having the female screw hole 37 thinner. Thus, the height in the third direction Z of the boss portion 32 b protruding toward the capacitor 19 of the inverter 10 in the partition portion 32 can be reduced. As a result, the capacitor 19 can be disposed close to the partition 32 without avoiding the boss 32 b.

  Here, as described above, the female screw hole 37 is provided at a position near the refrigerant flow path 36 in the partition portion 32. For this reason, the converter 20 fixed to the partition portion 32 using the female screw hole 37 is disposed in the vicinity of the refrigerant flow path 36 of the partition portion 32. On the other hand, similarly to the condenser 19 of the inverter 10, it is disposed close to the refrigerant flow path 36 of the partition portion 32 at a position close to the female screw hole 37. Therefore, a desired cooling effect can be obtained not only for converter 20 but also for capacitor 19.

As described above, according to the power conversion device 1 of the present embodiment, when the converter 20 which is one power converter is fixed to the partition 32 by the fastening bolt 51, the capacitor of the inverter 10 which is the other power converter It can suppress that the cooling effect of 19 falls. Therefore, the cooling performance of both the capacitor 19 and the converter 20 can be improved.
Further, by reducing the dimension in the third direction Z of the boss portion 32 b in the partition portion 32, the external dimension of the power conversion device 1 in the third direction Z can be miniaturized.
Further, since the male screw shaft 52 of the fastening bolt 51 is directly screwed to the partition portion 32 without using a dedicated nut or the like, the number of parts can be reduced and the structure can be simplified.

  In the present embodiment, the capacitor 19 constituting the inverter 10 (the power converter located on the tip end of the male screw shaft 52 of the fastening bolt 51 among the inverter 10 and the converter 20) is a virtual through the male screw shaft 52 of the fastening bolt 51. It is disposed on the axis L. The virtual axis L extends in the third direction Z. That is, the virtual axis L overlaps the capacitor 19. Thus, the condenser 19 can be disposed closer to the refrigerant flow path 36 of the partition portion 32, and the cooling effect of the condenser 19 can be enhanced.

  In the present embodiment, the male screw shaft 52 of the fastening bolt 51 is configured to be screwed with the female screw hole 37 without piercing the female screw hole 37 toward the front end side of the shaft. That is, the axial end of the male screw shaft 52 is disposed in the female screw hole 37, or the axial tip of the male screw shaft 52 is flush with the open end of the female screw hole 37. In the present configuration, the female screw hole 37 is closed by a thin sheet member 54 from the axial tip end side of the male screw shaft 52. According to the sheet member 54, foreign matter can be prevented from entering the first space 33 of the case 30 through the female screw hole 37 when the power conversion device 1 is assembled. By reducing the thickness of the sheet member 54, the external dimensions of the power conversion device 1 in the third direction Z can be reduced.

  Furthermore, the sheet member 54 is configured to be in contact with both the capacitor 19 and the partition portion 32 that constitute the inverter 10. The sheet member 54 is made of a heat conductive material. This thermally conductive sheet has higher thermal conductivity than air, and typically has such a characteristic that the thermal conductivity is in the range of 0.8 W / m · K or more. As a result, the heat generated in the capacitor 19 is easily transmitted to the partition portion 32 through the sheet member 54, and the cooling effect of the capacitor 19 can be further enhanced.

  In addition, as a heat conductive material of the sheet member 54, a silicone type material, an acrylic type material, a urethane type material, a ceramic type material, a graphite type material etc. are mentioned typically. Such a material also has flexibility, so it easily adheres to the capacitor 19 and the partition 32 and is advantageous in heat exchange.

  As shown in FIG. 5, the above-described inverter 10 constitutes an inverter circuit 10a which is a power conversion circuit that converts DC power supplied from the DC power supply B1 into AC power. In the inverter circuit 10 a, the switching operation (on / off operation) of the plurality of semiconductor modules 11 is controlled by the control circuit board 17.

  In the present embodiment, the booster 18 b of the inverter circuit 10 a which is a power conversion circuit is configured by the reactor 18 and the two semiconductor modules 11 a. The reactor 18 is a passive element using an inductor. The booster 10b has a function of boosting the voltage of the DC power supply B1 by the switching operation (on / off operation) of the semiconductor module 11a.

  On the other hand, conversion part 10c of inverter circuit 10a which is a power conversion circuit is constituted by capacitor 19 and six semiconductor modules 11b. The converter 10c has a function of converting DC power boosted by the booster 10b into AC power by switching operation (on / off operation) of the semiconductor module 11b. The three-phase AC motor M for driving the vehicle is driven by the AC power obtained by the conversion unit 10c.

  Converter 20 is connected to DC power supply B1, and is used to step-down the voltage of DC power supply B1 to charge auxiliary battery B2 having a lower voltage than DC power supply B1. The auxiliary battery B2 is used as a power supply of various devices mounted on the vehicle.

  The invention is not limited to the exemplary embodiments described above, but various applications and modifications are conceivable without departing from the object of the invention. For example, the following embodiments to which the above embodiment is applied can be implemented.

  In the above embodiment, although the case where the fixed portion (base portion 21) of converter 20 is fixed to partition portion 32 by fastening bolt 51 has been described, inverter 10 is used instead of or in addition to the fixed portion of converter 20. It is also possible to adopt a configuration in which the fixed parts of the elements that make up the part are fixed to the partition part 32 by the same members as the fastening bolts 51. As an element which constitutes inverter 10, reactor 18 and capacitor 19 are mentioned, for example. In the case of the capacitor 19, in the fixed portion of the resin case in which the metal collar is integrated, the collar is provided with a through hole such as the bolt insertion hole 22 and the male screw shaft of the fastening bolt is in this through hole A configuration may be adopted in which the female screw hole of the partition 32 is screwed in the inserted state.

  Although the case where the partition part 32 is comprised as a part of case 30 was described in said embodiment, the partition part 32 may be comprised as a member separate from case 30. FIG.

  In the above embodiment, although the case where the capacitor 19 is disposed on the imaginary axis L passing through the male screw shaft 52 of the fastening bolt 51 has been described, at least one of a plurality of elements constituting the inverter 10 For example, at least one of the reactor 18 and the capacitor 19 may be disposed on the imaginary axis L.

  In the above embodiment, although the case where the male screw shaft 52 of the fastening bolt 51 is screwed with the female screw hole 37 without penetrating the female screw hole 37 toward the shaft tip side is described, The male screw shaft 52 of the fastening bolt 51 may pierce through the female screw hole 37.

  In the above embodiment, the case where the sheet member 54 for closing the female screw hole 37 is made of a material having high thermal conductivity is described, but in the case where the purpose is only to prevent the entry of foreign matter, the sheet member 54 is It can also be made of a less conductive material.

  In the above embodiment, although the case where the sheet member 54 contacts both the capacitor 19 and the partition portion 32 has been described, the sheet member 54 may be added to the partition portion 32 as needed to form the inverter 10. It may be configured to be in contact with at least one of them (for example, at least one of reactor 18 and capacitor 19). In addition, a configuration in which the sheet member 54 contacts only the partition portion 32 without contacting the capacitor 19 may be employed. In the case of this configuration, heat generated in the first space 33 of the case 30 is more easily transmitted to the partition portion 32 cooled by the refrigerant flowing through the refrigerant flow path 36 than when a sheet member having low thermal conductivity is used. As a result, the ambient temperature of the first space 33 can be reduced.

1 Power Converter 10 First Power Converter (Inverter)
19 capacitor 20 second power converter (converter)
21 Base part (fixed part)
22 bolt insertion hole 30 case 32 partition part 36 refrigerant flow path 37 female screw hole 51 fastening bolt 52 male screw shaft 54 seat member L virtual axis

Claims (3)

A first power converter (10) and a second power converter (20) each performing power conversion;
A case (30) accommodating the first power converter and the second power converter;
A partition portion (32) which partitions the first power converter and the second power converter housed in the case and which constitutes a refrigerant flow path (36) through which the refrigerant flows;
A fastening bolt (51) for securing the fixed portion (21) of at least one of the first power converter and the second power converter to the partition portion;
The male screw shaft (52) of the fastening bolt is inserted into the bolt insertion hole (22) provided in the fixed part, and screwed into the female screw hole (37) provided in the partition part,
The female screw hole penetrates the partition portion ,
Among the first power converter and the second power converter, the power converter positioned on the tip end side of the male screw shaft of the fastening bolt is disposed on a virtual axis (L) passing through the male screw shaft,
The fastening bolt is configured to be screwed with the female screw hole without the male screw shaft penetrating the female screw hole toward the axial tip end, and the female screw hole is a thin sheet from the axial tip side of the male screw shaft Power converter (1) closed by a member (54 ). The sheet member is made of a thermally conductive material, the power conversion device according to claim 1. The sheet member is configured to be in contact with both the power converter located on the tip end side of the male screw shaft of the fastening bolt among the first power converter and the second power converter and the partition portion. The power conversion device according to claim 2 , wherein

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